Apparatus for the preparation of carbon conductors



PatentedJaJn. 17,1882.

A K; BOHM.

APPARATUS FOR THE PREPARATION OF CARBON UONDUOTORS.

(No Model.)

'INVENTOR; i5; ,7 flaw- N. PETERS. PilolirLmmgmp @TTEST, w 0/;-

.KJ'NITED I STATES PATENT OFFICE.

LUDYVIG K. BDHM, OF NEW YORK, N. Y., ASSIGNOR TO THE UNITED STATES ELECTRIC LIGHTING COMPANY, OF SAME PLACE.

APPARATUS FQRTHE PREPARATION OF CARBON CONDUCTORS'. 7

SPECIFICATIDN forming part of Letters Patent No. 252,351, dated January 17, 1882.

To all whom it may concern:

Be it known that I, LUDWIG K. BonM, of the city, county, and State of New York, have invented certain new and useful Improvements in Apparatus for the Preparation of the Car bon Conductors for Incandescent Electric Lamps, of which the following is a specification, reference being had to the drawings accompanying and forming a part thereof.

When blanks of paper, wood, or fibrous material are carbonized in a muffle strips of tough and flexible carbonare obtained which are peculiarly well adapted for purposes of incandescent lighting; but as the resistances of the individual strips vary considerably it is necessary to subject them to a process for equalizing their resistances, so that all may give approximately the same intensity of light.

For this purpose a number of tem porary clamping devices have been arranged under a receiver from which the air is exhausted, and into which a carbonaceous gas has been admitted. In these clamps carbonized slips are inserted and electrically heated until, by the deposition of carbon from the surrounding gas, their resistance is reduced to a standard limit.

From a large receiver-such as would be required for any considerable number of carbons-it is a matter of the greatest ditliculty to withdraw all theair. It therefore happens that the carbons heated to incandescence in the presence of aquanti'ty of oxygen, however small, will require a much longer time to ac- -ment of a Sprengel or Geisler pump; and,

third,the element of cost is so greatly reduced as to be of comparatively little importance.

In the accompanying drawings myimprovcd apparatus is illustrated on a reduced scale. It

Application filed June 23, 1881. (No model.)

vided at any suitable point with a two-way.

cock, H.

The operation of the device is as follows: The receptacles B B are closed by the plugs or stoppers G, to which have been attached the carbons F. The tube Gris then by the cock H connectedwith a Sprengel or Geisler pump and the air withdrawn as perfectly as possible. The cock is then turned to admit from a suitable receiver a carbonaceous gas, which in its turn is pumped out, and this piccess repeated as many times as desired, until an attenuated atmosphere of the carbon vapor is distributed throughout the whole interior of the apparatus. The carbons are then heated, either successively or simultaneously, by a current passed through the wires D D, until each is brought to the predetermined standard of resistance and luminosity. Air

now being admitted the stoppers are readily removed and the carbons taken ofl' and permanently attached to the supporting conductors of the lamps.

By this apparatus the carbons are treated and tested under the same conditions of atmospheric pressure that obtain in the finished lamps. All blackening of the lamp-globes is avoided and the carbons prepared in large numbers rapidly and economically.

I do not claim, broadly, in this application a ground-glass stopper containing the con-' ducting-wires, to which an incandescent car ICO ' adapted to be-combined with devices for ex- 1. The combination of two or more separate cent lamps, the combination, with main tube carbon depositing or testing receivers, each G and horizontal tube A, of the several bulbs, closed by a plug or stopper containing the me- B B, closed. by plugs or stoppers containing tallic conductors to which the carbons are at-- the conducting-Wires D D, carrying clamps tached, the several receivers being connected for retaining the ends of carbon conductors, by a pipe or. tube common to them all, and i as and for the purposes described.

- In testimony w'hereofI have hereunto set hausting the air and for introdncingagas into my hand this 17th day of May, 1881.

the said receivers, as and for the purpose set LUDWIG K. BOHM. forth.

2. In an apparatus for electrically heating and testing carbon conductors for incandes- Witnesses:

ERNST NEUPERT, GUSTAV MILLER. 

